bighead knapweed USDA PLANTS Symbol: CEMA9
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Centaurea macrocephala Puschk. ex Willd.

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Taxonomic Rank: Magnoliopsida: Asterales: Asteraceae
Synonym(s): big yellow centaurea, big-headed knapweed
Native Range: Caucasus (BAIL);

Appearance
Centaurea macrocephala is a large, perennial herb that grows on sturdy root stock and can reach 5 ft. (1.5 m) tall. Various common names including Lemon Fluff, Globe Centaury and Pineapple Thistle.
Foliage
Broadly lance-shaped leaves with sharp, pointed tips are rough to the touch and up to 15 in. (38.1 cm) long at the base of the plant.
Flowers
Single, showy, bright yellow flower head at tops of stems. Bracts (found under the flower head) are golden brown and fringed. Flowering occurs from July to September.
Fruit
Reproduces by seed which can be spread by wind, passing animals, humans, vehicles or equipment. It can re-sprout from woody root crown.
Ecological Threat
Centaurea macrocephala will out-compete grasses and other forage species, reducing food sources for wildlife and livestock. It is very difficult to remove once established. It is native to Turkey.

Selected Images from Invasive.orgView All Images at Invasive.org


Flower(s);
Nicole Kimmel, Government of Alberta, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Nicole Kimmel, Government of Alberta, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Nicole Kimmel, Government of Alberta, Bugwood.org
Additional Resolutions & Image Usage

Infestation;
Nicole Kimmel, Government of Alberta, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Nicole Kimmel, Government of Alberta, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State List
This map identifies those states that list this species on their invasive species list or law.


Invasive Listing Sources:
Pacific Northwest Exotic Pest Plant Council, 1998
WeedUS - Database of Plants Invading Natural Areas in the United States